How Many Runs For A Built C-4

93gtmustang

10 Year Member
Oct 21, 2006
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I have a Dynamic Racing Built Transmission to handle up to 750 HP C-4 Reverse Manual. 4200 Stall Converter. Transmission cooler.
My car is a 93 Mustang 345 flywheel hp, 300 torque. 3.90 gears. Weighs 3080 lbs. with driver.
I have 187 runs on it with no issues.

Is there anyone on here that has had any experience with a combo like this and how many runs they got out of it? I'm just curious on how far they usually go before freshening. Thanks!

I highly recommend Dynamic Racing. Great product and customer support. I emailed the owner who is JR and he responded below.

(187 and running great? Glad to hear that! I would say, if it is running perfect and fluid looks good, keep going. You could play it safe and freshen now,
but i don't see an issue if you want to keep an eye on the fluid condition and pay close attention to the shift quality. After 200, if you start to notice any higher temps
or the slightest flares on the 2-3 especially, be ready to get 'er freshened.
 
The limit on how long it will last is dictated by the case strength and the HP you are putting through it.
I have yet to see an aftermarket SFI case for the C-4.
This is the reason I went with a PG based build. I wanted to stay with a Ford based automatic, but none of them have an aftermarket SFI case, and the stock case just does not hold up well to 1K power.
Add in the PITA with dealing with a SFI shield for the trans with clearance issues and such.
At your power level, I doubt that you will ever have any issues.
 
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The limit on how long it will last is dictated by the case strength and the HP you are putting through it.
I have yet to see an aftermarket SFI case for the C-4.
This is the reason I went with a PG based build. I wanted to stay with a Ford based automatic, but none of them have an aftermarket SFI case, and the stock case just does not hold up well to 1K power.
Add in the PITA with dealing with a SFI shield for the trans with clearance issues and such.
At your power level, I doubt that you will ever have any issues.
Exactly what you said. At my power level.
The transmission has twice the power capability of the motor.
That's why I'm wondering how many runs I can expect to get before I have to get it freshened.
Thanks!
 
Just watch the fluid and temps. If you have not dropped the pan and changed the filter that may be something you consider.

For reference my buddy had an 86 GT and ran a built reverse manual valve body C4 with a Neil Chance converter behind a 408 on nitrous on 10.5W slicks. Car was pretty fast and had a nasty hole shot. He would run it half the race season and then it would get clutches. Full rebuild would be over the winter. He always wanted to put a power glide in it but sold the car before that happened.
 
Just watch the fluid and temps. If you have not dropped the pan and changed the filter that may be something you consider.

For reference my buddy had an 86 GT and ran a built reverse manual valve body C4 with a Neil Chance converter behind a 408 on nitrous on 10.5W slicks. Car was pretty fast and had a nasty hole shot. He would run it half the race season and then it would get clutches. Full rebuild would be over the winter. He always wanted to put a power glide in it but sold the car before that happened.
Thanks!
The fluid is changed every year with Red Line Synthetic Racing Fluid and the Filter is cleaned.
Your Buddy was throwing a lot at the 86 GT! Wow!
I guess I should have kept the T-5Z in it. Less Maintenance. I ran it for 10 years with the same clutch. Just changed the fluid every other year.
The guy I had sold it to in 2016, put a heavy-duty clutch in it, raced it for a few seasons., I bought it back in 2020 and raced it for a season.
When it comes time to freshen the C-4, I have to find someone to take it out and put it back in because I don't have a lift or the know-how.
And 6 hours of driving to drop it off and pick it back up.
 
We ran our first C4 for eight years (13's down to the 11's) our second one we freshened up twice over a 12 year period...10's and dipped into the 9's.
It was all PA Racing stuff at the time.
Thats great there.
do you remember which PA transmission you had.?
 
Thats great there.
do you remember which PA transmission you had.?
We ran the pan filled C4...we bought all the best pieces that they had for the C4 as I could afford them.
We had a local transmission shop (a sponsor of ours) assemble it and away we went.